Ratchet spanners must have efficient direction control devices to control the operation directions of the ratchet wheel efficiently.
In U.S. Pat. No. 6,609,444, a direction control device of a ratchet spanner is disclosed. The direction control device includes a spanner body, a ratchet wheel, a brake block and a direction control unit. A head portion of the spanner body is installed with a receiving chamber. A lateral side of the receiving chamber has a braking groove and a direction control groove. The direction control groove is communicated to the braking groove. The receiving chamber serves to receive the ratchet wheel and the braking groove serves to receiver a brake block which is engaged to the ratchet wheel. The direction control unit includes a direction control block and an elastic ejecting device. The direction control block receives the elastic ejecting device. A T shape stopper is installed on the direction control block for preventing the elastic ejecting device to fall out as switching the resisting position of the brake block.
In this prior art direction control device of a ratchet spanner, the elastic ejecting device is used to change the resisting position of the brake block. The elastic ejecting device is formed mainly by a spring. Therefore, the T shape stopper on the direction control block can confine the elastic ejecting device from falling. However when the resisting direction of the brake block is switched by the direction control block, the spring of the elastic ejecting device will suffer from a greater transversal force. Since the spring cannot absorb the transversal force, it is possible that the spring will deform. Thus, the direction control device of a ratchet spanner will be destroyed. Furthermore, only one end of the T shaper stopper resists against the direction control block. It is possibly that the T shape stopper will fall out and thus it is impossible for preventing the elastic ejecting device from falling out. In summary, the prior art is not practical and thus it is necessary to be improved.